text: // SPDX-License-Identifier: MIT
  /*
   * Copyright © 2019 Intel Corporation
   */
  
  #include <drm/intel-gtt.h>
  
  #include "intel_gt_debugfs.h"
  
  #include "gem/i915_gem_lmem.h"
  #include "i915_drv.h"
  #include "intel_context.h"
  #include "intel_gt.h"
  #include "intel_gt_buffer_pool.h"
  #include "intel_gt_clock_utils.h"
  #include "intel_gt_pm.h"
  #include "intel_gt_requests.h"
  #include "intel_migrate.h"
  #include "intel_mocs.h"
  #include "intel_pm.h"
  #include "intel_rc6.h"
  #include "intel_renderstate.h"
  #include "intel_rps.h"
  #include "intel_uncore.h"
  #include "shmem_utils.h"
  #include "pxp/intel_pxp.h"
  
  void __intel_gt_init_early(struct intel_gt *gt, struct drm_i915_private *i915)
  {
  	spin_lock_init(&gt->irq_lock);
  
  	mutex_init(&gt->tlb_invalidate_lock);
  
  	INIT_LIST_HEAD(&gt->closed_vma);
  	spin_lock_init(&gt->closed_lock);
  
  	init_llist_head(&gt->watchdog.list);
  	INIT_WORK(&gt->watchdog.work, intel_gt_watchdog_work);
  
  	intel_gt_init_buffer_pool(gt);
  	intel_gt_init_reset(gt);
  	intel_gt_init_requests(gt);
  	intel_gt_init_timelines(gt);
  	intel_gt_pm_init_early(gt);
  
  	intel_uc_init_early(&gt->uc);
  	intel_rps_init_early(&gt->rps);
  }
  
  void intel_gt_init_early(struct intel_gt *gt, struct drm_i915_private *i915)
  {
  	gt->i915 = i915;
  	gt->uncore = &i915->uncore;
  }
  
  int intel_gt_probe_lmem(struct intel_gt *gt)
  {
  	struct drm_i915_private *i915 = gt->i915;
  	struct intel_memory_region *mem;
  	int id;
  	int err;
  
  	mem = intel_gt_setup_lmem(gt);
  	if (mem == ERR_PTR(-ENODEV))
  		mem = intel_gt_setup_fake_lmem(gt);
  	if (IS_ERR(mem)) {
  		err = PTR_ERR(mem);
  		if (err == -ENODEV)
  			return 0;
  
  		drm_err(&i915->drm,
  			"Failed to setup region(%d) type=%d\n",
  			err, INTEL_MEMORY_LOCAL);
  		return err;
  	}
  
  	id = INTEL_REGION_LMEM;
  
  	mem->id = id;
  
  	intel_memory_region_set_name(mem, "local%u", mem->instance);
  
  	GEM_BUG_ON(!HAS_REGION(i915, id));
  	GEM_BUG_ON(i915->mm.regions[id]);
  	i915->mm.regions[id] = mem;
  
  	return 0;
  }
  
  void intel_gt_init_hw_early(struct intel_gt *gt, struct i915_ggtt *ggtt)
  {
  	gt->ggtt = ggtt;
  }
  
  static const struct intel_mmio_range icl_l3bank_steering_table[] = {
  	{ 0x00B100, 0x00B3FF },
  	{},
  };
  
  static const struct intel_mmio_range xehpsdv_mslice_steering_table[] = {
  	{ 0x004000, 0x004AFF },
  	{ 0x00C800, 0x00CFFF },
  	{ 0x00DD00, 0x00DDFF },
  	{ 0x00E900, 0x00FFFF }, /* 0xEA00 - OxEFFF is unused */
  	{},
  };
  
  static const struct intel_mmio_range xehpsdv_lncf_steering_table[] = {
  	{ 0x00B000, 0x00B0FF },
  	{ 0x00D800, 0x00D8FF },
  	{},
  };
  
  static const struct intel_mmio_range dg2_lncf_steering_table[] = {
  	{ 0x00B000, 0x00B0FF },
  	{ 0x00D880, 0x00D8FF },
  	{},
  };
  
  static u16 slicemask(struct intel_gt *gt, int count)
  {
  	u64 dss_mask = intel_sseu_get_subslices(&gt->info.sseu, 0);
  
  	return intel_slicemask_from_dssmask(dss_mask, count);
  }
  
  int intel_gt_init_mmio(struct intel_gt *gt)
  {
  	struct drm_i915_private *i915 = gt->i915;
  
  	intel_gt_init_clock_frequency(gt);
  
  	intel_uc_init_mmio(&gt->uc);
  	intel_sseu_info_init(gt);
  
  	/*
  	 * An mslice is unavailable only if both the meml3 for the slice is
  	 * disabled *and* all of the DSS in the slice (quadrant) are disabled.
  	 */
  	if (HAS_MSLICES(i915))
  		gt->info.mslice_mask =
  			slicemask(gt, GEN_DSS_PER_MSLICE) |
  			(intel_uncore_read(gt->uncore, GEN10_MIRROR_FUSE3) &
  			 GEN12_MEML3_EN_MASK);
  
  	if (IS_DG2(i915)) {
  		gt->steering_table[MSLICE] = xehpsdv_mslice_steering_table;
  		gt->steering_table[LNCF] = dg2_lncf_steering_table;
  	} else if (IS_XEHPSDV(i915)) {
  		gt->steering_table[MSLICE] = xehpsdv_mslice_steering_table;
  		gt->steering_table[LNCF] = xehpsdv_lncf_steering_table;
  	} else if (GRAPHICS_VER(i915) >= 11 &&
  		   GRAPHICS_VER_FULL(i915) < IP_VER(12, 50)) {
  		gt->steering_table[L3BANK] = icl_l3bank_steering_table;
  		gt->info.l3bank_mask =
  			~intel_uncore_read(gt->uncore, GEN10_MIRROR_FUSE3) &
  			GEN10_L3BANK_MASK;
  	} else if (HAS_MSLICES(i915)) {
  		MISSING_CASE(INTEL_INFO(i915)->platform);
  	}
  
  	return intel_engines_init_mmio(gt);
  }
  
  static void init_unused_ring(struct intel_gt *gt, u32 base)
  {
  	struct intel_uncore *uncore = gt->uncore;
  
  	intel_uncore_write(uncore, RING_CTL(base), 0);
  	intel_uncore_write(uncore, RING_HEAD(base), 0);
  	intel_uncore_write(uncore, RING_TAIL(base), 0);
  	intel_uncore_write(uncore, RING_START(base), 0);
  }
  
  static void init_unused_rings(struct intel_gt *gt)
  {
  	struct drm_i915_private *i915 = gt->i915;
  
  	if (IS_I830(i915)) {
  		init_unused_ring(gt, PRB1_BASE);
  		init_unused_ring(gt, SRB0_BASE);
  		init_unused_ring(gt, SRB1_BASE);
  		init_unused_ring(gt, SRB2_BASE);
  		init_unused_ring(gt, SRB3_BASE);
  	} else if (GRAPHICS_VER(i915) == 2) {
  		init_unused_ring(gt, SRB0_BASE);
  		init_unused_ring(gt, SRB1_BASE);
  	} else if (GRAPHICS_VER(i915) == 3) {
  		init_unused_ring(gt, PRB1_BASE);
  		init_unused_ring(gt, PRB2_BASE);
  	}
  }
  
  int intel_gt_init_hw(struct intel_gt *gt)
  {
  	struct drm_i915_private *i915 = gt->i915;
  	struct intel_uncore *uncore = gt->uncore;
  	int ret;
  
  	gt->last_init_time = ktime_get();
  
  	/* Double layer security blanket, see i915_gem_init() */
  	intel_uncore_forcewake_get(uncore, FORCEWAKE_ALL);
  
  	if (HAS_EDRAM(i915) && GRAPHICS_VER(i915) < 9)
  		intel_uncore_rmw(uncore, HSW_IDICR, 0, IDIHASHMSK(0xf));
  
  	if (IS_HASWELL(i915))
  		intel_uncore_write(uncore,
  				   MI_PREDICATE_RESULT_2,
  				   IS_HSW_GT3(i915) ?
  				   LOWER_SLICE_ENABLED : LOWER_SLICE_DISABLED);
  
  	/* Apply the GT workarounds... */
  	intel_gt_apply_workarounds(gt);
  	/* ...and determine whether they are sticking. */
  	intel_gt_verify_workarounds(gt, "init");
  
  	intel_gt_init_swizzling(gt);
  
  	/*
  	 * At least 830 can leave some of the unused rings
  	 * "active" (ie. head != tail) after resume which
  	 * will prevent c3 entry. Makes sure all unused rings
  	 * are totally idle.
  	 */
  	init_unused_rings(gt);
  
  	ret = i915_ppgtt_init_hw(gt);
  	if (ret) {
  		DRM_ERROR("Enabling PPGTT failed (%d)\n", ret);
  		goto out;
  	}
  
  	/* We can't enable contexts until all firmware is loaded */
  	ret = intel_uc_init_hw(&gt->uc);
  	if (ret) {
  		i915_probe_error(i915, "Enabling uc failed (%d)\n", ret);
  		goto out;
  	}
  
  	intel_mocs_init(gt);
  
  out:
  	intel_uncore_forcewake_put(uncore, FORCEWAKE_ALL);
  	return ret;
  }
  
  static void rmw_set(struct intel_uncore *uncore, i915_reg_t reg, u32 set)
  {
  	intel_uncore_rmw(uncore, reg, 0, set);
  }
  
  static void rmw_clear(struct intel_uncore *uncore, i915_reg_t reg, u32 clr)
  {
  	intel_uncore_rmw(uncore, reg, clr, 0);
  }
  
  static void clear_register(struct intel_uncore *uncore, i915_reg_t reg)
  {
  	intel_uncore_rmw(uncore, reg, 0, 0);
  }
  
  static void gen6_clear_engine_error_register(struct intel_engine_cs *engine)
  {
  	GEN6_RING_FAULT_REG_RMW(engine, RING_FAULT_VALID, 0);
  	GEN6_RING_FAULT_REG_POSTING_READ(engine);
  }
  
  void
  intel_gt_clear_error_registers(struct intel_gt *gt,
  			       intel_engine_mask_t engine_mask)
  {
  	struct drm_i915_private *i915 = gt->i915;
  	struct intel_uncore *uncore = gt->uncore;
  	u32 eir;
  
  	if (GRAPHICS_VER(i915) != 2)
  		clear_register(uncore, PGTBL_ER);
  
  	if (GRAPHICS_VER(i915) < 4)
  		clear_register(uncore, IPEIR(RENDER_RING_BASE));
  	else
  		clear_register(uncore, IPEIR_I965);
  
  	clear_register(uncore, EIR);
  	eir = intel_uncore_read(uncore, EIR);
  	if (eir) {
  		/*
  		 * some errors might have become stuck,
  		 * mask them.
  		 */
  		DRM_DEBUG_DRIVER("EIR stuck: 0x%08x, masking\n", eir);
  		rmw_set(uncore, EMR, eir);
  		intel_uncore_write(uncore, GEN2_IIR,
  				   I915_MASTER_ERROR_INTERRUPT);
  	}
  
  	if (GRAPHICS_VER(i915) >= 12) {
  		rmw_clear(uncore, GEN12_RING_FAULT_REG, RING_FAULT_VALID);
  		intel_uncore_posting_read(uncore, GEN12_RING_FAULT_REG);
  	} else if (GRAPHICS_VER(i915) >= 8) {
  		rmw_clear(uncore, GEN8_RING_FAULT_REG, RING_FAULT_VALID);
  		intel_uncore_posting_read(uncore, GEN8_RING_FAULT_REG);
  	} else if (GRAPHICS_VER(i915) >= 6) {
  		struct intel_engine_cs *engine;
  		enum intel_engine_id id;
  
  		for_each_engine_masked(engine, gt, engine_mask, id)
  			gen6_clear_engine_error_register(engine);
  	}
  }
  
  static void gen6_check_faults(struct intel_gt *gt)
  {
  	struct intel_engine_cs *engine;
  	enum intel_engine_id id;
  	u32 fault;
  
  	for_each_engine(engine, gt, id) {
  		fault = GEN6_RING_FAULT_REG_READ(engine);
  		if (fault & RING_FAULT_VALID) {
  			drm_dbg(&engine->i915->drm, "Unexpected fault\n"
  				"\tAddr: 0x%08lx\n"
  				"\tAddress space: %s\n"
  				"\tSource ID: %d\n"
  				"\tType: %d\n",
  				fault & PAGE_MASK,
  				fault & RING_FAULT_GTTSEL_MASK ?
  				"GGTT" : "PPGTT",
  				RING_FAULT_SRCID(fault),
  				RING_FAULT_FAULT_TYPE(fault));
  		}
  	}
  }
  
  static void gen8_check_faults(struct intel_gt *gt)
  {
  	struct intel_uncore *uncore = gt->uncore;
  	i915_reg_t fault_reg, fault_data0_reg, fault_data1_reg;
  	u32 fault;
  
  	if (GRAPHICS_VER(gt->i915) >= 12) {
  		fault_reg = GEN12_RING_FAULT_REG;
  		fault_data0_reg = GEN12_FAULT_TLB_DATA0;
  		fault_data1_reg = GEN12_FAULT_TLB_DATA1;
  	} else {
  		fault_reg = GEN8_RING_FAULT_REG;
  		fault_data0_reg = GEN8_FAULT_TLB_DATA0;
  		fault_data1_reg = GEN8_FAULT_TLB_DATA1;
  	}
  
  	fault = intel_uncore_read(uncore, fault_reg);
  	if (fault & RING_FAULT_VALID) {
  		u32 fault_data0, fault_data1;
  		u64 fault_addr;
  
  		fault_data0 = intel_uncore_read(uncore, fault_data0_reg);
  		fault_data1 = intel_uncore_read(uncore, fault_data1_reg);
  
  		fault_addr = ((u64)(fault_data1 & FAULT_VA_HIGH_BITS) << 44) |
  			     ((u64)fault_data0 << 12);
  
  		drm_dbg(&uncore->i915->drm, "Unexpected fault\n"
  			"\tAddr: 0x%08x_%08x\n"
  			"\tAddress space: %s\n"
  			"\tEngine ID: %d\n"
  			"\tSource ID: %d\n"
  			"\tType: %d\n",
  			upper_32_bits(fault_addr), lower_32_bits(fault_addr),
  			fault_data1 & FAULT_GTT_SEL ? "GGTT" : "PPGTT",
  			GEN8_RING_FAULT_ENGINE_ID(fault),
  			RING_FAULT_SRCID(fault),
  			RING_FAULT_FAULT_TYPE(fault));
  	}
  }
  
  void intel_gt_check_and_clear_faults(struct intel_gt *gt)
  {
  	struct drm_i915_private *i915 = gt->i915;
  
  	/* From GEN8 onwards we only have one 'All Engine Fault Register' */
  	if (GRAPHICS_VER(i915) >= 8)
  		gen8_check_faults(gt);
  	else if (GRAPHICS_VER(i915) >= 6)
  		gen6_check_faults(gt);
  	else
  		return;
  
  	intel_gt_clear_error_registers(gt, ALL_ENGINES);
  }
  
  void intel_gt_flush_ggtt_writes(struct intel_gt *gt)
  {
  	struct intel_uncore *uncore = gt->uncore;
  	intel_wakeref_t wakeref;
  
  	/*
  	 * No actual flushing is required for the GTT write domain for reads
  	 * from the GTT domain. Writes to it "immediately" go to main memory
  	 * as far as we know, so there's no chipset flush. It also doesn't
  	 * land in the GPU render cache.
  	 *
  	 * However, we do have to enforce the order so that all writes through
  	 * the GTT land before any writes to the device, such as updates to
  	 * the GATT itself.
  	 *
  	 * We also have to wait a bit for the writes to land from the GTT.
  	 * An uncached read (i.e. mmio) seems to be ideal for the round-trip
  	 * timing. This issue has only been observed when switching quickly
  	 * between GTT writes and CPU reads from inside the kernel on recent hw,
  	 * and it appears to only affect discrete GTT blocks (i.e. on LLC
  	 * system agents we cannot reproduce this behaviour, until Cannonlake
  	 * that was!).
  	 */
  
  	wmb();
  
  	if (INTEL_INFO(gt->i915)->has_coherent_ggtt)
  		return;
  
  	intel_gt_chipset_flush(gt);
  
  	with_intel_runtime_pm_if_in_use(uncore->rpm, wakeref) {
  		unsigned long flags;
  
  		spin_lock_irqsave(&uncore->lock, flags);
  		intel_uncore_posting_read_fw(uncore,
  					     RING_HEAD(RENDER_RING_BASE));
  		spin_unlock_irqrestore(&uncore->lock, flags);
  	}
  }
  
  void intel_gt_chipset_flush(struct intel_gt *gt)
  {
  	wmb();
  	if (GRAPHICS_VER(gt->i915) < 6)
  		intel_gtt_chipset_flush();
  }
  
  void intel_gt_driver_register(struct intel_gt *gt)
  {
  	intel_rps_driver_register(&gt->rps);
  
  	intel_gt_debugfs_register(gt);
  }
  
  static int intel_gt_init_scratch(struct intel_gt *gt, unsigned int size)
  {
  	struct drm_i915_private *i915 = gt->i915;
  	struct drm_i915_gem_object *obj;
  	struct i915_vma *vma;
  	int ret;
  
  	obj = i915_gem_object_create_lmem(i915, size, I915_BO_ALLOC_VOLATILE);
  	if (IS_ERR(obj))
  		obj = i915_gem_object_create_stolen(i915, size);
  	if (IS_ERR(obj))
  		obj = i915_gem_object_create_internal(i915, size);
  	if (IS_ERR(obj)) {
  		drm_err(&i915->drm, "Failed to allocate scratch page\n");
  		return PTR_ERR(obj);
  	}
  
  	vma = i915_vma_instance(obj, &gt->ggtt->vm, NULL);
  	if (IS_ERR(vma)) {
  		ret = PTR_ERR(vma);
  		goto err_unref;
  	}
  
  	ret = i915_ggtt_pin(vma, NULL, 0, PIN_HIGH);
  	if (ret)
  		goto err_unref;
  
  	gt->scratch = i915_vma_make_unshrinkable(vma);
  
  	return 0;
  
  err_unref:
  	i915_gem_object_put(obj);
  	return ret;
  }
  
  static void intel_gt_fini_scratch(struct intel_gt *gt)
  {
  	i915_vma_unpin_and_release(&gt->scratch, 0);
  }
  
  static struct i915_address_space *kernel_vm(struct intel_gt *gt)
  {
  	if (INTEL_PPGTT(gt->i915) > INTEL_PPGTT_ALIASING)
  		return &i915_ppgtt_create(gt, I915_BO_ALLOC_PM_EARLY)->vm;
  	else
  		return i915_vm_get(&gt->ggtt->vm);
  }
  
  static int __engines_record_defaults(struct intel_gt *gt)
  {
  	struct i915_request *requests[I915_NUM_ENGINES] = {};
  	struct intel_engine_cs *engine;
  	enum intel_engine_id id;
  	int err = 0;
  
  	/*
  	 * As we reset the gpu during very early sanitisation, the current
  	 * register state on the GPU should reflect its defaults values.
  	 * We load a context onto the hw (with restore-inhibit), then switch
  	 * over to a second context to save that default register state. We
  	 * can then prime every new context with that state so they all start
  	 * from the same default HW values.
  	 */
  
  	for_each_engine(engine, gt, id) {
  		struct intel_renderstate so;
  		struct intel_context *ce;
  		struct i915_request *rq;
  
  		/* We must be able to switch to something! */
  		GEM_BUG_ON(!engine->kernel_context);
  
  		ce = intel_context_create(engine);
  		if (IS_ERR(ce)) {
  			err = PTR_ERR(ce);
  			goto out;
  		}
  
  		err = intel_renderstate_init(&so, ce);
  		if (err)
  			goto err;
  
  		rq = i915_request_create(ce);
  		if (IS_ERR(rq)) {
  			err = PTR_ERR(rq);
  			goto err_fini;
  		}
  
  		err = intel_engine_emit_ctx_wa(rq);
  		if (err)
  			goto err_rq;
  
  		err = intel_renderstate_emit(&so, rq);
  		if (err)
  			goto err_rq;
  
  err_rq:
  		requests[id] = i915_request_get(rq);
  		i915_request_add(rq);
  err_fini:
  		intel_renderstate_fini(&so, ce);
  err:
  		if (err) {
  			intel_context_put(ce);
  			goto out;
  		}
  	}
  
  	/* Flush the default context image to memory, and enable powersaving. */
  	if (intel_gt_wait_for_idle(gt, I915_GEM_IDLE_TIMEOUT) == -ETIME) {
  		err = -EIO;
  		goto out;
  	}
  
  	for (id = 0; id < ARRAY_SIZE(requests); id++) {
  		struct i915_request *rq;
  		struct file *state;
  
  		rq = requests[id];
  		if (!rq)
  			continue;
  
  		if (rq->fence.error) {
  			err = -EIO;
  			goto out;
  		}
  
  		GEM_BUG_ON(!test_bit(CONTEXT_ALLOC_BIT, &rq->context->flags));
  		if (!rq->context->state)
  			continue;
  
  		/* Keep a copy of the state's backing pages; free the obj */
  		state = shmem_create_from_object(rq->context->state->obj);
  		if (IS_ERR(state)) {
  			err = PTR_ERR(state);
  			goto out;
  		}
  		rq->engine->default_state = state;
  	}
  
  out:
  	/*
  	 * If we have to abandon now, we expect the engines to be idle
  	 * and ready to be torn-down. The quickest way we can accomplish
  	 * this is by declaring ourselves wedged.
  	 */
  	if (err)
  		intel_gt_set_wedged(gt);
  
  	for (id = 0; id < ARRAY_SIZE(requests); id++) {
  		struct intel_context *ce;
  		struct i915_request *rq;
  
  		rq = requests[id];
  		if (!rq)
  			continue;
  
  		ce = rq->context;
  		i915_request_put(rq);
  		intel_context_put(ce);
  	}
  	return err;
  }
  
  static int __engines_verify_workarounds(struct intel_gt *gt)
  {
  	struct intel_engine_cs *engine;
  	enum intel_engine_id id;
  	int err = 0;
  
  	if (!IS_ENABLED(CONFIG_DRM_I915_DEBUG_GEM))
  		return 0;
  
  	for_each_engine(engine, gt, id) {
  		if (intel_engine_verify_workarounds(engine, "load"))
  			err = -EIO;
  	}
  
  	/* Flush and restore the kernel context for safety */
  	if (intel_gt_wait_for_idle(gt, I915_GEM_IDLE_TIMEOUT) == -ETIME)
  		err = -EIO;
  
  	return err;
  }
  
  static void __intel_gt_disable(struct intel_gt *gt)
  {
  	intel_gt_set_wedged_on_fini(gt);
  
  	intel_gt_suspend_prepare(gt);
  	intel_gt_suspend_late(gt);
  
  	GEM_BUG_ON(intel_gt_pm_is_awake(gt));
  }
  
  int intel_gt_wait_for_idle(struct intel_gt *gt, long timeout)
  {
  	long remaining_timeout;
  
  	/* If the device is asleep, we have no requests outstanding */
  	if (!intel_gt_pm_is_awake(gt))
  		return 0;
  
  	while ((timeout = intel_gt_retire_requests_timeout(gt, timeout,
  							   &remaining_timeout)) > 0) {
  		cond_resched();
  		if (signal_pending(current))
  			return -EINTR;
  	}
  
  	return timeout ? timeout : intel_uc_wait_for_idle(&gt->uc,
  							  remaining_timeout);
  }
  
  int intel_gt_init(struct intel_gt *gt)
  {
  	int err;
  
  	err = i915_inject_probe_error(gt->i915, -ENODEV);
  	if (err)
  		return err;
  
  	intel_gt_init_workarounds(gt);
  
  	/*
  	 * This is just a security blanket to placate dragons.
  	 * On some systems, we very sporadically observe that the first TLBs
  	 * used by the CS may be stale, despite us poking the TLB reset. If
  	 * we hold the forcewake during initialisation these problems
  	 * just magically go away.
  	 */
  	intel_uncore_forcewake_get(gt->uncore, FORCEWAKE_ALL);
  
  	err = intel_gt_init_scratch(gt,
  				    GRAPHICS_VER(gt->i915) == 2 ? SZ_256K : SZ_4K);
  	if (err)
  		goto out_fw;
  
  	intel_gt_pm_init(gt);
  
  	gt->vm = kernel_vm(gt);
  	if (!gt->vm) {
  		err = -ENOMEM;
  		goto err_pm;
  	}
  
  	intel_set_mocs_index(gt);
  
  	err = intel_engines_init(gt);
  	if (err)
  		goto err_engines;
  
  	err = intel_uc_init(&gt->uc);
  	if (err)
  		goto err_engines;
  
  	err = intel_gt_resume(gt);
  	if (err)
  		goto err_uc_init;
  
  	err = __engines_record_defaults(gt);
  	if (err)
  		goto err_gt;
  
  	err = __engines_verify_workarounds(gt);
  	if (err)
  		goto err_gt;
  
  	intel_uc_init_late(&gt->uc);
  
  	err = i915_inject_probe_error(gt->i915, -EIO);
  	if (err)
  		goto err_gt;
  
  	intel_migrate_init(&gt->migrate, gt);
  
  	intel_pxp_init(&gt->pxp);
  
  	goto out_fw;
  err_gt:
  	__intel_gt_disable(gt);
  	intel_uc_fini_hw(&gt->uc);
  err_uc_init:
  	intel_uc_fini(&gt->uc);
  err_engines:
  	intel_engines_release(gt);
  	i915_vm_put(fetch_and_zero(&gt->vm));
  err_pm:
  	intel_gt_pm_fini(gt);
  	intel_gt_fini_scratch(gt);
  out_fw:
  	if (err)
  		intel_gt_set_wedged_on_init(gt);
  	intel_uncore_forcewake_put(gt->uncore, FORCEWAKE_ALL);
  	return err;
  }
  
  void intel_gt_driver_remove(struct intel_gt *gt)
  {
  	__intel_gt_disable(gt);
  
  	intel_migrate_fini(&gt->migrate);
  	intel_uc_driver_remove(&gt->uc);
  
  	intel_engines_release(gt);
  
  	intel_gt_flush_buffer_pool(gt);
  }
  
  void intel_gt_driver_unregister(struct intel_gt *gt)
  {
  	intel_wakeref_t wakeref;
  
  	intel_rps_driver_unregister(&gt->rps);
  
  	intel_pxp_fini(&gt->pxp);
  
  	/*
  	 * Upon unregistering the device to prevent any new users, cancel
  	 * all in-flight requests so that we can quickly unbind the active
  	 * resources.
  	 */
  	intel_gt_set_wedged_on_fini(gt);
  
  	/* Scrub all HW state upon release */
  	with_intel_runtime_pm(gt->uncore->rpm, wakeref)
  		__intel_gt_reset(gt, ALL_ENGINES);
  }
  
  void intel_gt_driver_release(struct intel_gt *gt)
  {
  	struct i915_address_space *vm;
  
  	vm = fetch_and_zero(&gt->vm);
  	if (vm) /* FIXME being called twice on error paths :( */
  		i915_vm_put(vm);
  
  	intel_wa_list_free(&gt->wa_list);
  	intel_gt_pm_fini(gt);
  	intel_gt_fini_scratch(gt);
  	intel_gt_fini_buffer_pool(gt);
  }
  
  void intel_gt_driver_late_release(struct intel_gt *gt)
  {
  	/* We need to wait for inflight RCU frees to release their grip */
  	rcu_barrier();
  
  	intel_uc_driver_late_release(&gt->uc);
  	intel_gt_fini_requests(gt);
  	intel_gt_fini_reset(gt);
  	intel_gt_fini_timelines(gt);
  	intel_engines_free(gt);
  }
  
  /**
   * intel_gt_reg_needs_read_steering - determine whether a register read
   *     requires explicit steering
   * @gt: GT structure
   * @reg: the register to check steering requirements for
   * @type: type of multicast steering to check
   *
   * Determines whether @reg needs explicit steering of a specific type for
   * reads.
   *
   * Returns false if @reg does not belong to a register range of the given
   * steering type, or if the default (subslice-based) steering IDs are suitable
   * for @type steering too.
   */
  static bool intel_gt_reg_needs_read_steering(struct intel_gt *gt,
  					     i915_reg_t reg,
  					     enum intel_steering_type type)
  {
  	const u32 offset = i915_mmio_reg_offset(reg);
  	const struct intel_mmio_range *entry;
  
  	if (likely(!intel_gt_needs_read_steering(gt, type)))
  		return false;
  
  	for (entry = gt->steering_table[type]; entry->end; entry++) {
  		if (offset >= entry->start && offset <= entry->end)
  			return true;
  	}
  
  	return false;
  }
  
  /**
   * intel_gt_get_valid_steering - determines valid IDs for a class of MCR steering
   * @gt: GT structure
   * @type: multicast register type
   * @sliceid: Slice ID returned
   * @subsliceid: Subslice ID returned
   *
   * Determines sliceid and subsliceid values that will steer reads
   * of a specific multicast register class to a valid value.
   */
  static void intel_gt_get_valid_steering(struct intel_gt *gt,
  					enum intel_steering_type type,
  					u8 *sliceid, u8 *subsliceid)
  {
  	switch (type) {
  	case L3BANK:
  		GEM_DEBUG_WARN_ON(!gt->info.l3bank_mask); /* should be impossible! */
  
  		*sliceid = 0;		/* unused */
  		*subsliceid = __ffs(gt->info.l3bank_mask);
  		break;
  	case MSLICE:
  		GEM_DEBUG_WARN_ON(!gt->info.mslice_mask); /* should be impossible! */
  
  		*sliceid = __ffs(gt->info.mslice_mask);
  		*subsliceid = 0;	/* unused */
  		break;
  	case LNCF:
  		GEM_DEBUG_WARN_ON(!gt->info.mslice_mask); /* should be impossible! */
  
  		/*
  		 * An LNCF is always present if its mslice is present, so we
  		 * can safely just steer to LNCF 0 in all cases.
  		 */
  		*sliceid = __ffs(gt->info.mslice_mask) << 1;
  		*subsliceid = 0;	/* unused */
  		break;
  	default:
  		MISSING_CASE(type);
  		*sliceid = 0;
  		*subsliceid = 0;
  	}
  }
  
  /**
   * intel_gt_read_register_fw - reads a GT register with support for multicast
   * @gt: GT structure
   * @reg: register to read
   *
   * This function will read a GT register.  If the register is a multicast
   * register, the read will be steered to a valid instance (i.e., one that
   * isn't fused off or powered down by power gating).
   *
   * Returns the value from a valid instance of @reg.
   */
  u32 intel_gt_read_register_fw(struct intel_gt *gt, i915_reg_t reg)
  {
  	int type;
  	u8 sliceid, subsliceid;
  
  	for (type = 0; type < NUM_STEERING_TYPES; type++) {
  		if (intel_gt_reg_needs_read_steering(gt, reg, type)) {
  			intel_gt_get_valid_steering(gt, type, &sliceid,
  						    &subsliceid);
  			return intel_uncore_read_with_mcr_steering_fw(gt->uncore,
  								      reg,
  								      sliceid,
  								      subsliceid);
  		}
  	}
  
  	return intel_uncore_read_fw(gt->uncore, reg);
  }
  
  void intel_gt_info_print(const struct intel_gt_info *info,
  			 struct drm_printer *p)
  {
  	drm_printf(p, "available engines: %x\n", info->engine_mask);
  
  	intel_sseu_dump(&info->sseu, p);
  }
  
  struct reg_and_bit {
  	i915_reg_t reg;
  	u32 bit;
  };
  
  static struct reg_and_bit
  get_reg_and_bit(const struct intel_engine_cs *engine, const bool gen8,
  		const i915_reg_t *regs, const unsigned int num)
  {
  	const unsigned int class = engine->class;
  	struct reg_and_bit rb = { };
  
  	if (drm_WARN_ON_ONCE(&engine->i915->drm,
  			     class >= num || !regs[class].reg))
  		return rb;
  
  	rb.reg = regs[class];
  	if (gen8 && class == VIDEO_DECODE_CLASS)
  		rb.reg.reg += 4 * engine->instance; /* GEN8_M2TCR */
  	else
  		rb.bit = engine->instance;
  
  	rb.bit = BIT(rb.bit);
  
  	return rb;
  }
  
  void intel_gt_invalidate_tlbs(struct intel_gt *gt)
  {
  	static const i915_reg_t gen8_regs[] = {
  		[RENDER_CLASS]			= GEN8_RTCR,
  		[VIDEO_DECODE_CLASS]		= GEN8_M1TCR, /* , GEN8_M2TCR */
  		[VIDEO_ENHANCEMENT_CLASS]	= GEN8_VTCR,
  		[COPY_ENGINE_CLASS]		= GEN8_BTCR,
  	};
  	static const i915_reg_t gen12_regs[] = {
  		[RENDER_CLASS]			= GEN12_GFX_TLB_INV_CR,
  		[VIDEO_DECODE_CLASS]		= GEN12_VD_TLB_INV_CR,
  		[VIDEO_ENHANCEMENT_CLASS]	= GEN12_VE_TLB_INV_CR,
  		[COPY_ENGINE_CLASS]		= GEN12_BLT_TLB_INV_CR,
  	};
  	struct drm_i915_private *i915 = gt->i915;
  	struct intel_uncore *uncore = gt->uncore;
  	struct intel_engine_cs *engine;
  	enum intel_engine_id id;
  	const i915_reg_t *regs;
  	unsigned int num = 0;
  
  	if (I915_SELFTEST_ONLY(gt->awake == -ENODEV))
  		return;
  
  	if (GRAPHICS_VER(i915) == 12) {
  		regs = gen12_regs;
  		num = ARRAY_SIZE(gen12_regs);
  	} else if (GRAPHICS_VER(i915) >= 8 && GRAPHICS_VER(i915) <= 11) {
  		regs = gen8_regs;
  		num = ARRAY_SIZE(gen8_regs);
  	} else if (GRAPHICS_VER(i915) < 8) {
  		return;
  	}
  
  	if (drm_WARN_ONCE(&i915->drm, !num,
  			  "Platform does not implement TLB invalidation!"))
  		return;
  
  	GEM_TRACE("\n");
  
  	assert_rpm_wakelock_held(&i915->runtime_pm);
  
  	mutex_lock(&gt->tlb_invalidate_lock);
  	intel_uncore_forcewake_get(uncore, FORCEWAKE_ALL);
  
  	for_each_engine(engine, gt, id) {
  		/*
  		 * HW architecture suggest typical invalidation time at 40us,
  		 * with pessimistic cases up to 100us and a recommendation to
  		 * cap at 1ms. We go a bit higher just in case.
  		 */
  		const unsigned int timeout_us = 100;
  		const unsigned int timeout_ms = 4;
  		struct reg_and_bit rb;
  
  		rb = get_reg_and_bit(engine, regs == gen8_regs, regs, num);
  		if (!i915_mmio_reg_offset(rb.reg))
  			continue;
  
  		intel_uncore_write_fw(uncore, rb.reg, rb.bit);
  		if (__intel_wait_for_register_fw(uncore,
  						 rb.reg, rb.bit, 0,
  						 timeout_us, timeout_ms,
  						 NULL))
  			drm_err_ratelimited(&gt->i915->drm,
  					    "%s TLB invalidation did not complete in %ums!\n",
  					    engine->name, timeout_ms);
  	}
  
  	/*
  	 * Use delayed put since a) we mostly expect a flurry of TLB
  	 * invalidations so it is good to avoid paying the forcewake cost and
  	 * b) it works around a bug in Icelake which cannot cope with too rapid
  	 * transitions.
  	 */
  	intel_uncore_forcewake_put_delayed(uncore, FORCEWAKE_ALL);
  	mutex_unlock(&gt->tlb_invalidate_lock);
  }
  